Maintenance Method of Chucks
The chuck is a mechanical device on the machine tool to clamp the workpiece; and a machine tool accessory that can clamp and position the workpiece firmly by use of the radial movement of movable jaw uniformly distributed on the chuck. It is learned that a chuck is composed of chuck body, movable jaw and jaw driving mechanism three parts. The diameter of a chuck can range from 65mm to 1,500mm. There is a through hole in the center, which facilitates the workpiece or bar stock to pass through; and the back of the chuck has a cylindrical or short taper-shape structure, which can be connected to the end of the shaft of the machine tool via a flange plate. The chuck is usually installed on the lathe, cylindrical grinder and internal grinder and can also be used together with all kinds of dividing apparatuses on millers and drillers.
For the daily maintenance of the chuck, we list the following methods:
1.In order to keep the chuck still have good precision after a long time of use, lubrication is very important. Incorrect or unsuitable lubrication will cause some problems, such as abnormal function at low pressure, weakened chucking power, bad clamping precision, abnormal wear and being stuck, so the chuck must be lubricated correctly.
2.Polish at least once with molybdenum disulfide grease (black in color), inject the grease into the oil nozzle of the chuck until the grease overfill the clamping jaw surface of the inner bore of the chuck (protective jacket of the inner hole and place connecting the nut). But, if the chuck is rotating at a high speed or lots of water-based cutting oil is used for processing, more lubrication is needed, and specifically it depends on actual situations.
3.At the end of the work, be sure to clean the chuck body and the slip surface with a blower gun or similar tool.
4.Remove the chuck and disassemble it for cleaning at least every 6 months, keep the slip surface of the clamping jaw clean and lubricate it, prolonging the service life of the chuck. But, the chuck should be thoroughly cleaned once or for times at least every 2 months if the chuck is used to cut cast iron, check whether any parts are broken or worn, change a new one if any is broken or worn seriously. After examination, lubricate it enough and then reassemble it.
5.For different workpiece, you should use different clamping methods or choose specially made clamps. Three-jaw chuck is a kind of universal clamp and jig. If using it to clamp irregular or strange workpiece, it may damage the chuck and if the chuck pressure is abnormal, it will make the chuck in a high-pressure state; or the chuck still clamps the workpiece after the machine is turned off, they all will reduce the service life of the chuck. Therefore, when you find the gap between the chucks is too large, be sure to replace a new chuck immediately!
6.The use of rust-proof cutting oil can prevent the inside of the chuck from rusting. Because rust will reduce the clamping force of the chuck and make the chuck cannot clamp the workpiece firmly.